Artificial-limb-locking device



Aug. 6,1929. J. F, RQWLEY 1,723,491

ARTIFICIAL LIME LOCKING DEVICE Filed Oct. 5. 1927 Patented Aug. 6, 1929.

PATENT OFFICE.

JAMES F. ROWLEY, OF CHICAGO, ILLINOIS.

ARTIFICIAL-LIMB-LOCKING DEVICE.

Application filed October 5, 1927.

This invention relates to artificial limbs oi the type in which thethigh and shin sections can be manually secured against relative angularmovement in one direction.

The main objects of this invention are to provide an improved form ofartificial limb wherein the shin and thigh sections can be lockedagainst angular relative movement by the limb operating suspender; toprovide an improved limb of this character in which the danger ofbuckling forward of the limb is entirely eliminated; and to provide animproved torm of locking mechanism which is durable and substantial inconstruction and economical to manufacture.

An illustrative embodiment oi this invention is shown in theaccompanying drawings, in which Figure 1 is a vertical section of theknee "joint portions of an artificial limb, the back check and lockingmechanism being takenon the line 1-1 oi Fig. 2.

Fig. 2 is an elevation of the improved looking mechanism with thesuspender controls left out for the sake oi clearness.

Fig. 3 is a reduced front elevation ofthe artificial limb showing thelimb operating suspender controls.

The construction shown herein is of the same general character as thatshown in my copending application Serial No. 201,353, filed June 25,1927, with certain important improvements resulting from actualexperience in the use oi knee joint locking mechanisms. Heretofore, inthe construction of artificial limbs wherein a flexible member had itstwo ends attached to the thigh section and the medial portion loopedaround looking mechanism carried on the shin section, it has been foundthat in some instances where the wearer attempted to lock the sec tionagainst relative angular movement while the sections were in pivotalmovement at the time of locking, that the limb would sometimes buckleforward unless the wearer kept a strain on the operating suspender andlocking means. This action of the limb is caused by the end of theflexible member attached to tlie'rear of the limb pulling the memberthrough the locking mechanism in a direction which tends to break thegrip of the cam lock on the flexible member and thus release thesections from locked position.

Serial No. 224,138.

In the construction shown in the drawings, a thigh section 1 ispivotally connected by a knee bolt 2 to a shin section 3 in the usualmanner. A back check 4 in the form of a fiat metal strap for limitingthe relative angular movement of the sections in one direction, issecured at its lower end 5 to the in side rear wall of the shin section3 by a wood screw (3 threaded in a pair of leather washers 7. The backcheck 4 extends forwardly and then upwardly into the lower end of thethigh section 1, the upper end thereof being bent to surround and bejournalled on the knee bolt 2 with the end thereol extending downwardlyand rearwardly to form a bearing 8 for a pin 9 which carries a pair offorwardly extending cheek plates lo and 11.

The forward ends of the cheek plates 10 and 11 have a double roller 12'journalled therebetween on a pin 13, thus providing a suspender bearinglocated in advance of the kneebolt 2 and which is adapted to receivesuspender thongs 14 of a limb-operating shoulder suspender 15. Means areprovided for holding the thongs 14 in the grooved wheels 12 at all timesand comprise a sleeve 16 journalled on a pin 17 carried by the plates 10and 11, in close proximity to the suspender bearing 12. a

The suspended thongs 14 after passing around the roller 12 then leadupwardly and to the rear, over the knee bolt 2, and then downwardlyaround a double roller wheel. 18 carried by a flexible strap 19 whichhas its lower end secured at 20 to the exterior rear side of the shinsection 3 in the usual manner. The thongs 1 1 then pass outwardlythrough the customary slot in the rear of the lower end of the thighsection and lead upwardly for attachment to the shoulder suspender 15.

A flexible strap member 21 which may be entirely of leather orof leatherwith a thin, flexible steel backing strip has its upper end attached byscrews 22 or the like to the exterior surface of the knee portion 23 ofthe thigh section 1, the lowerend thereof extending downwardly andrearwardly into the :inl terior of the upper end of the shin section 3,such lower end hanging free and not being attached to anythin 1 Meansare provided for gripping the flexible member 21 and thus securing theshin the flexible member 21 slides backwardly and and thigh sectionsagainst relative angular movement in one direction, and comprises aforwardly projecting arm 24 riveted or otherwise rigidly secured to theback check 4 and having a pair of laterally disposed downwardly turnedears to carry a pin 25 upon which is journalled a cam 26 integrallyformed with cam arm 27, the flexible member 21 being adapted to extendbetween the arm 24 and cam 26, so as to slide thercthrough bifurcatedarms 30 and 31 extending outwardly and then downwardly and then inwardlyin the form of a stirrup, the ends thereof embracing the outer end ofcam'lever 27 and having a pin 32 passingtherethrough for-pivotallyconnecting the link 28 to the cam lever 27. r

Yielding means are'providedfor normally urging the link 28 downwardly,thus normally retaining the locking mechanism in released position, andcomprises a coil compression spring 33 surrounding the link 28, whichhas one end bearing against the under side of the lug 29 and the otherend thereof bearing against a washer 34 retained on the link 28 by "apin 35.

In the operation of this artificial limb, the user manipulates the thighand shin sections in walking in'the usual manner by means of thesuspender 15 and suspender thongs 14,

thus simulating the natural movements of the human limb. I

During this normal movementof the limb,

forwardly through the locking mechanism which is normally held inreleased position by thecompression spring 33 pressing downwardly on thelink 28. V

In cases where it is desired to take a step forward while the sectionsare-bent angular- 1y with respect to each other, as for instance inwalking up a steep hill or taking a step toa higher plane, the wearerlifts his shoulder an abnormal amount, thus raising the forwardsuspender bearing 12 upwardly and lifting'the link 28 "upwardly againstthe action of thecompression spring 33.

Upward movement of the link 28 raises the'cam lever 27 thus causing thecam 26 to grip the flexible member 21 thus securing the sections againstrelative angular movement in a forward or buckling direction.

Although; but one specific embodiment of this invention has beenhereinshown and described, it will be understood that numerous details of theconstruction shown may be altered or omitted without departim from thespirit of this invention as defined by the following claims.

I claim:

1. An artificial limb comprising pivotally connected shin and thighsections, locking means on oneof said sections, a flexible memberattached at one end only to the other of said sections and arranged toslide over said locking means when said sections are pivotally operated,and a suspender having eonnections for actuating said locking means togrip said flexible member and secure said sections against relativeangular movement.

2. An artificial limb comprising pivotally connected shin and thighsections, a suspender for operating said limb, a yielding bearing forsaid suspender located in advance of said pivotal connection, lockingmeans on one of said sections, a flexible member attached to the otherof said sections and arranged to slide over said locking means when saidsections are pivotally operated, and eonnections between said yieldingsuspender bearing and said locking means for actuating said lockingmeans to grip said flexible member and secure said sections againstrelative angular movement.

3. An artificial limb comprising pivotally connected shin and thighsections, a back check secured to said shin section and journalled onsaid pivotal connection, a suspender bearing pivotally mounted on saidback check, a suspender engaging said bearing for operating said limb,yielding means for said suspender bearing normally opposing the pull ofsaid suspender, locking means on said back check, a flexible memberattached to said thigh section and arranged to slide over said lockmgmeans when said sections are pivotally operated, and connections betweenfor actuating said locking means to grip said flexible member and securesaid sections against relative angular movement, and automatic means forreleasing said locking means.

5. An artificial limb comprising pivotally connected shin and thighsections, a back check for limiting the relative angular movement ofsaid sections in one direction, lockingmeans on said back check, aflexible memher attached to one of said sections and arranged to slideover said locking means when, said sections are pi'votally operated, anda suspender for actuating said locking means to grip said flexiblemember whereby said sections are secured against relative angularmovement.

6. An artificial limb com nkising pivotally connected shin and thighsections, locking means on, one of said sections, a flexible memberattached to the other of said sections and arranged to slide over saidlocking means when said sections are pivotally operated, a back check, alever pivotally attached at one end to the back check and having asuspender bearing at the other end thereoi', a limb operating suspen derengaging said bearing, a link connecting said lever with said lockingmeans, yi elding means normally holding sai d locking means in releasedposition, said suspemler being adapted to actuate said lever, link, andlocking means to grip said flexible member and secure said sectionsagainst relative angular movement.

7. An artificial limb comprising pivotally connected shin and thighsections, locking means on one of said sections, a flexible memberattached to the other of said sections and arranged to slide over saidlocking means when said sections are pivotally operated, a back check, alever pivotally attached to the back check at one end and having asuspender bearing at the other end thereof, a limb operating suspenderengaging said bearing, a link connecting said lever with said lockingmeans, yielding means on said link normally holding said locking meansin released position, said suspender being adapted to actuate saidlever, link, and locking means to grip said flexible member and securesaid sections against relative angular movement.

8. An artificial limb comprising pivotally connected shin and thighsections, locking means on one of said sections, a flexible memherattached to the other of said sections and arranged to slide over saidlocking means when said sections are pivotally operated, a back check, alever pivotally attached at one end to the back check and having asuspender hearing at the other end thereof, a limb operating suspenderengaging said bearing, a link connecting said lever with said lockingmeans, a back-check for limiting the move-- ment of said sections in onedirection, yielding means bearing between said link and said back-checknormally holding said locking means in released position, said suspenderbeing adapted to actuate said lever, link, and locking means to gripsaid flexible meinliier and secure said sections against relativeangular movement.

9. An artificial limb comprising pivotally connected shin and thighsections, a backcheck for limiting the relative angular movement of saidsections in one direction, a flex- -ible member attached to said thighsection,

means on said back-check for gripping said flexible member whereby saidsections are secured against relative angular movement in the otherdirection, and a suspender having connections for causing said means togrip the flexible member.

10. An artificial limb comprising pivotally connected shin and thighsections, a backcheck for limiting the relative angular move ment ofsaid sections in one direction, a flex-v ible member attached to theexterior knee portion of said thigh section, means on said back-checkfor gripping said flexible member whereby said sections are securedagainst relative angular movementin the other direction, and a suspenderhaving connections for causing said means to grip the flexible member.

S igned at Chicago this 3rd day of October 1921.

JAMES F. ROWLEY.

